Dionysus the Meager

Dionysius the Meager (Latin: Dionysius Exiguus; c. 460/5 - 525/50) was a monk, scholar and mathematician of Byzantine origin, known above all for being the creator of the calculation of the Anno Domini ('year of the Lord') to calculate the date of Easter, replacing the previous Diocletian era, a measure used in the Julian calendar and in the Gregorian calendar that succeeded and perfected it.

A native of Scythia Minor —in the present territory of Dobruja, between Romania and Bulgaria— he was a member of a community of Scythia monks concentrated in Tomis, the main city of Scythia Minor. Since the beginning of the VI century he lived in Rome, where he became a member of the Roman Curia.

Life

Very little is known about the life of Dionysus. A large part of them come from Cassiodoro's work Institutiones divinarum et saecularium litterarum , and others from a few autobiographical allusions in the prologues of his works, dedications or letter headings.

In Latin he was called Dionysius Exiguus ('Dionysius the Dwarf' or 'the Little One'), a nickname that appears at the beginning of some of his works, but it is possible that it is work of some later copyist. Cassiodorus never used the cognomen and the earliest occurrence of it is in the early eighth century, in a quote from Bede in his Ecclesiastical History of the English People (HE 5.21). In a dedicatory letter to Pope Hormisdas, Dionysus refers to himself as mea parvitas, emphasizing his smallness or insignificance compared to the greatness of the Pope. Even if Dionysus himself used it, it is likely a form of monastic humility rather than an allusion to his physical appearance. Bede also refers to him with the title abbas, surely as a formula of respect that does not necessarily mean that Dionysus at some point managed a monastery. In the prologue to an enlargement of his Computus dated to the year 616 he even calls himself "the most learned abbot of Rome".

Cassiodorus was a wealthy senator and adviser to the Ostrogothic King Theodoric the Great who, a convert to Christianity, had studied with Dionysus and was his personal friend. In his Institutiones , Cassiodorus says of Dionysus that he was originally from "Scythia", although educated as a Roman. Scythia had been a Roman province and, thanks to the dedication of his translation of two letters from Cyril of Alexandria to his former fellow monks, the ancient Greek colony of Tomis can be identified as his place of origin.

Dionysius, who wrote that he had never met Pope Gelasius I, must have arrived in Rome some time after Gelasius's death, around the year 500, where he was safely staying during the pontificate of Hormisdas, between 514 and 523. how long he remained there is unknown, but he was surely dead in the 550s, when Cassiodorus wrote the Institutiones. In this work Cassiodorus does not mention the work on the calendar for which Dionysus is best known today, although perhaps he himself, or someone close to him, was the author of the first mention of a year known as ab anno Domini, text in which the year 562 is used as an example (PL 69, 1249).

The origin of the metonic structure of his paschal table

The 95-year paschal table of Dionysus the Meager owes its excellence to the special structure of its 19-year lunar cycle in its sixth column F (being closely related to the essentially same structure but ordered clearly from his cycle of 19 epacts in his third column C); this special structure is an application of the Metonic cycle (discovered in the fifth century BC in Babylon or by Meto) in the Julian calendar. It is for this reason that the structure in question and similar lunar cycles are also called metonics and metonics, respectively. The Metonic structure for 19-year lunar cycles was invented around AD 260 by the great Alexandrian computist Anatolius of Laodicea. Anatolian's 19-year Metonic lunar cycle, however, differs from Dionysius the Meager's, which is equal to the Metonic 19-year lunar cycle. The classic 19-year Alexandrian lunar cycle, being the close variant of Theophilus' 19-year lunar cycle introduced by the Alexandrian computist Anianus and adopted by Bishop Cyril of Alexandria.

Your Easter table and the Anno Domini

Although Dionysus is famous for being credited with introducing the Christian era as a system for numbering the years, his work was focused on obtaining an extension of the tables used until then for the calculation of the date of Easter. As this date depends on the lunar cycles, it is necessary to calculate the period of time in which a certain number of synodic months of approximately 29.5 days coincide with a certain number of solar years of about 365.25 days. Dionysius used the most accurate of its time, the Metonic cycle of 19 years. In the preface to his table, Dionysius claims to have used five such cycles to obtain Easter dates for a period of 95 years.

It is only in the context of the use of the Paschal table that Dionysius used Incarnation-based dating and does not appear to have intended for it to become a new chronological basis. Nor does he cite specific dates outside of his calculations except in a letter addressed to the then chancellor of Pope John I, and in turn future pope, Boniface, where he explains details about the paschal moon of that year, which he says is the 14th of a year. cycle of 19 and the 4th of an indictional cycle, which in his tables corresponds to the year 242 of the Diocletian era, that is, the year 526. Dionysius designates the year 525 as that of the consulate of Probus, which indicates that it was the consular year, official at the time, the basic frame of reference that he himself used.

He devised a new year numbering system to replace the Diocletian years used in the old Easter tables, because he did not want to carry on the memory of a dictator who had persecuted Christians. The problem is that Dionysus was wrong by about 4 to 7 years when dating the reign of Herod I the Great, so he deduced that Jesus was born in the year 753 BC. or. c. from the founding of Rome (ab urbe condita), when it must have happened around 746 B.C. or. c.

This Anno Domini system became dominant in Western Europe only after it was used by the Venerable Bede to date events in his Ecclesiastical History of the English, which he completed. in the 731.

Calendar without year zero

Dionysius the Meager did not provide for the era of a year zero. This is not strange, since in early medieval Europe nobody knew the number zero. However, the presence of the Latin word nulla in the third column of his Easter table creates the impression that Dionysus the Meager knew that important number. But there is nothing from which it could be deduced that his null was a true zero (he didn't use it in his calculations anyway). In Europe it had to wait until the second millennium before the number zero became available, which the Arabs took from India and brought to the West.^{[citation needed]}

Actually, Dionysus doesn't talk about year zero because his introduction is a convention that helps in astronomical calculations, so it wasn't a mistake. The days before point 0 belong to the year -1 and the following days are already from +1. Therefore, the year 0 has no extension, it is only an instant between the years -1 and +1. The same as when the era called the Foundation of Rome begins, it begins with the year +1, and the previous year would be -1 of that era, but not 0.

Other works

Dionysius the Meager also made one of the first collections of canon law. He translated from Greek into Latin 401 canons, including the apostolic canons and the decrees of the councils of Nicaea, Constantinople, Chalcedon, and Sardica, and also a collection of 39 papal decrees, from Siricius to Anastasius II. These collections enjoyed great authority. in the West and still guide the administration of the Catholic Church.

He also wrote a treatise on elementary mathematics.^{[citation needed]}